In-Line Carbonation of Water-Base Beverages

ABSTRACT

The invention is directed to a device ( 1 ) and a process for dissolving a gas into a liquid like carbonating a water based beverage, comprising a pump ( 4 ) for the liquid, a mixing venture nozzle ( 8 ) with a main inlet ( 10 ) fluidly connected to the pump ( 4 ), at least one side inlet ( 14 ) connectable to a source of pressurized gas ( 6 ), and an outlet. The device ( 1 ) comprises also a conical flow restrictor ( 24 ) fluidly downstream of the mixing venture nozzle ( 8 ), and a pipe ( 20 ) of a length of at least 0.5 m fluidly interconnected between the mixing venture nozzle ( 8 ) and the flow restrictor ( 24 ).

TECHNICAL FIELD

The invention is directed to dissolving gas into a liquid, moreparticularly to the preparation of the water-based beverages, even moreparticularly to the in-line carbonation of such beverages.

BACKGROUND ART

Prior art patent document published WO 2009/021960 A1 discloses a devicefor the enrichment of a liquid stream with a gas, e.g. for thecarbonation of a beverage like water. The device comprises a flow mixerwith a venture nozzle having a rotationally symmetrical contraction andbeing flown through axially by the liquid stream. The device furthercomprises a lateral feed of the gas into the contraction of the venturenozzle. The gas feed comprises at least one gas channel with a reduceddiameter, ending laterally in the contraction of the venture nozzle insuch a way that the elongated longitudinal axis thereof is offset withregard to the longitudinal axis of the venture nozzle.

This teaching is interesting in that the venture nozzle is optimizedwith regard to the position and orientation of the gas channels. Theprocess of carbonation of water is however dependent on differentfactors like temperature and pressure. The presence of low temperatureis particularly favorable for carbonating water. This is why a coolingunit is provided in this teaching, upstream of the mixing venturenozzle. The presence of such a cooling unit is however disadvantageouswith regard to the manufacture and running costs of the device. In theabsence of such a unit, the amount of carbon dioxide dissolved in thewater by means of the device of this teaching can be too low, inparticular in the presence of warmer temperatures, e.g. duringsummertime.

Prior art patent documents published DE 10 2012 100 844 A1 discloses asimilar device for carbonating wine-based beverages. Similarly to thedevice of the previous document, this device comprises a cooling unitbetween the pump and the mixing chamber. Unlike in the previousdocument, this device comprises, in addition, a static mixer downstreamof the mixing chamber. This static mixer comprises a tube housing aseries of spiral-shaped mixing elements that are configured such thatthe liquid is subject to a pressure drop of about 0.5 bar between theinlet and the outlet of the static mixer. This static mixer is intendedto provide a high mixing rate of the carbon dioxide with the liquid. Itis also intended to avoid the formation of foam, thereby allowing aconvenient drawing of the carbonated liquid at the exit of the device.The working pressure in the mixing chamber is of about 2 bar, so thatthe liquid exits the static mixer with a pressure of about 1.5 bar.Similarly to the above document, this device has the inconvenient thatit requires a cooling unit. In addition, the static mixer is acomplicated element that causes a significant pressure drop and that canbe expensive in manufacture as well as in maintenance.

Prior art patent document published FR 2 949 355 B1 discloses device forcarbonating water-based beverages that is similar to the device of theprevious document. Indeed, it comprises also a static mixer downstreamof the mixing chamber, this static mixer creating an intendedprogressive pressure drop to progressively bring the liquid to apressure close to atmospheric pressure at the exit tap.

Prior art patent document published U.S. Pat. No. 5,842,600 disclosesalso a device for carbonating water or water-based beverages. Similarlyto the device of the two previous documents (DE 10 2012 100 844 A1 andFR 2 949 355 B1), it comprises a static mixer comprising a tube housinga series of spiral-shaped mixing elements.

SUMMARY OF INVENTION Technical Problem

The invention has for technical problem to provide an improvedenrichment of a liquid with gas, like carbonation of water-basedbeverages, i.e. an enrichment that is cheaper and achieves a satisfyingamount of gas dissolved in the beverage.

Technical solution

The invention is directed to a device for dissolving gas like carbondioxide into a liquid like a water-based beverage, comprising: a pumpfor the liquid; a mixing venture nozzle with a main inlet fluidlyconnected to the pump, at least one side inlet connectable to a sourceof pressurized gas, and an outlet; wherein the device further comprises:a conical flow restrictor fluidly connected downstream of the mixingventure nozzle; and a pipe of a length of at least 0.5 m fluidlyinterconnected between the mixing venture nozzle and the flowrestrictor.

The cone of the flow restrictor is preferably oriented so as to divergein the flow direction.

According to a preferred embodiment of the invention, the pipe is acorrugated pipe, preferably a flexible corrugated pipe, more preferablya flexible stainless steel corrugated pipe, even more preferably aflexible stainless steel corrugated pipe with a plastic external sleeve.

According to a preferred embodiment of the invention, the corrugatedpipe forms corrugation ridges with a height h that is comprised between5% and 20% of the internal diameter d of the pipe and/or with adistance/between adjacent ridges that is comprised between 5% and 30%,preferably between 10% and 20% of the internal diameter d of the pipe.

According to a preferred embodiment of the invention, the pipe has aninternal diameter d that is comprised between 5 mm and 25 mm, preferablybetween 8 mm and 20 mm, more preferably between 10 mm and 15 mm.

According to a preferred embodiment of the invention, the pipe has awall thickness e that is comprised between 0.15 mm and 0.3 mm.

According to a preferred embodiment of the invention, the pipe has alength that is of at least 0.8 m, preferably at least 1.0 m, morepreferably at least 1.2 m.

According to a preferred embodiment of the invention, the pipe has alength that is less than 5 m, preferably less than 2 m, more preferablyless than 1.5 m.

According to a preferred embodiment of the invention, the pipe is bentat several places over at least 90°, preferably over about 180°, so asto form a compact unit.

According to a preferred embodiment of the invention, the pump isconfigured to pressurize the liquid at a pressure of at least 8 bar,preferably 9 bar, more preferably 10 bar, between said pump and themixing venture nozzle.

According to a preferred embodiment of the invention, the conical flowrestrictor is configured to maintain a pressure in the pipe that iscomprised between 6 bar and 10 bar, preferably between 7 bar and 9 bar,while debiting the liquid.

According to a preferred embodiment of the invention, the flow sectionof the conical flow restrictor progressively increases in the directionof the flow.

According to a preferred embodiment of the invention, the conical flowrestrictor comprises a housing with a circular internal surface thatdiverges in the direction of the flow, and a conical element inside saidhousing delimiting with said diverging internal surface an annular flowsection.

According to a preferred embodiment of the invention, the minimal flowsection of the conical flow restrictor is comprised between 1 mm² and 10mm², preferably between 2 mm² and 8 mm², more preferably between 2.8 mm²and 5.6 mm².

According to a preferred embodiment of the invention, it comprises ashut-off valve fluidly between the conical flow restrictor and themixing venture nozzle.

According to a preferred embodiment of the invention, it furthercomprises a mixing chamber fluidly connected to the outlet of the mixingventure nozzle, the mixing chamber being preferably directly coupled tothe mixing venture nozzle so that said chamber is a direct extension ofthe outlet of said venture nozzle.

The invention is also directed to a process for dissolving a gas into aliquid like carbonating a water based beverage, comprising the followingsteps:

(a) pressurizing the liquid in a circuit comprising a mixing venturenozzle; and (b) adding the gas to said liquid flowing through the mixingventure nozzle by connecting at least one side inlet of said venturenozzle to a source of the pressurized gas; wherein the process comprisesproviding: a conical flow restrictor fluidly downstream of the mixingventure nozzle; and a pipe of a length of at least 0.5 m fluidlyinterconnected between the mixing venture nozzle and the flowrestrictor.

According to a preferred embodiment of the invention, the processcomprises using a device in accordance with the invention.

According to a preferred embodiment of the invention, step (b) compriseskeeping the pressure in the pipe between 6 bar and 10 bar, preferablybetween 7 bar and 9 bar, by means of the flow restrictor. Advantages ofthe invention

The invention is particularly interesting in that it permits to in-linedissolve gas into a liquid, e.g. carbonate water or water-basebeverages, by means of a device of a simple construction and stillachieving a high grade of gas dissolved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 discloses the architecture of a device for dissolving gas into aliquid, in accordance with the invention;

FIG. 2 is sectional view of the conical flow restrictor of the device ofFIG. 1;

FIG. 3 is a view of portion of corrugated flexible pipe that is presentbetween the flow restrictor and the mixing venture nozzle of the deviceof FIG. 1;

FIG. 4 is a general view of the device of FIG. 1, the device beingconnected to a source of pressurized carbon dioxide.

DESCRIPTION OF AN EMBODIMENT

The device 1 that is schematically illustrated in FIG. 1 comprises asource of liquid 2, e.g. a source of water-based beverage like water.This source can be a tank filled with such a liquid. In the case ofwater, it can also be a connection to a water distribution circuit. Thedevice 1 comprises also a pump 4 for pressurizing the liquid. The outletof the pump 4 is connected to a mixing venture nozzle 8. The nozzle 8comprises a body with an inlet 10, a throat 12 and an outlet 16. In theflow direction, the throat 12 converges from the inlet 10 to a minimumsection and then diverges to the outlet 16. The mixing venture nozzle 8comprises also lateral or side inlets 14 for the pressurized gas to bemixed with the liquid. The pressurized gas is stored in a tank or bottle6. The side inlets 14 extend essentially radially with regard to thelongitudinal axis (being vertical in the orientation of FIG. 1) of themixing venture nozzle 8. The conduits 14 join the throat 12 essentiallyat its minimum section, i.e. where the flowing speed of the liquid is atmaximum.

A mixing chamber 18 is connected to the outlet 16 of the mixing venturenozzle 8. In the present case, the mixing chamber 18 is coupled directlyto the body of the mixing venture nozzle 8 so that the outlet 16 of saidnozzle is fed directly in the chamber 18. This chamber 18 is preferablyelongate so as to allow the liquid and the gas to mix with each otherand thereby to allow at least a portion of the gas to be dissolved inthe liquid.

The exit of the mixing chamber 18 is connected to a unit 20 that isessentially made of a corrugated flexible pipe that is bent at severalplaces so as to form a compact unit. The details of the pipe will beprovided later in connection with FIGS. 3 and 4.

A shut-off valve 22 is connected at the exit of the piping unit 20 and acompensator or flow restrictor 24 is connected at the exit of theshut-off valve 22. The shut-off valve 22 can be manually orelectromagnetically operated.

A pressure-reducer 26 between the source of pressurized carbon dioxide 6and the inlets 14 on the mixing venture nozzle 8. This pressure-reduceris a proportional one in that it adapts the pressure of the gas to thepressure of the liquid that is pressurized by the pump 4.

FIG. 2 is a sectional view of the flow restrictor 24 of FIG. 1. Itcomprises a body 28 that is made of a main body 28 ¹ and of a cap 28 ²that cooperates with the main body so as to close it. The main body 28 ¹comprises an inlet 30 of the flow restrictor and forms a cavitydelimited by a diverging surface along the normal flow direction insidethat cavity. In the present illustration, this surface is conical alonga first portion and cylindrical along a second portion following thefirst one in the normal flow direction. The cap 28 ² comprises an outlet32 of the flow restrictor 24. It comprises also sealing means like agasket for cooperating in a water tight fashion with the main body 28 ¹.In the present example, the main body 28 ¹ and the cap 28 ² cooperatewith each other by means of quick coupling prongs and recesses. Aconical element 34 is housed in the cavity of the flow restrictor 24.The external surface of this element 34 is essentially complementarywith the internal surface of the housing. A gap is however providedbetween these two surfaces, this gap forming the flow section for theliquid. The conical element 34 is generally cone-shaped so as toessentially conform to the internal surface of the housing. Due to thediverging shape of the internal surface of the housing and of thecorresponding external surface of the conical element 34, the flowsection progressively increases along the flow direction, provided thatthe gap between these two surfaces remain constant or increases. In thepresent example, this gap progressively increases along the divergingportion of these surfaces, meaning that the flow section increases fortwo reasons, i.e. due to the increase of the diameter of the ring-shapedflow section, and also due to the increase of the width of thatring-shaped flow section. This gap can be comprised between 0.1 and 0.4mm, preferably between 0.12 and 2 mm, more preferably of about 0.15 mm(with a tolerance of ±0.05 mm).

Still in the present example, the flow section passed the divergingsurfaces, i.e. along the cylindrical surfaces is essentially constant.

The diverging surfaces allow a progressive deceleration of the liquidflow which avoids foaming. Indeed, a rapid pressure drop will releasedissolved gas in a sudden manner, leading to foaming up of the liquid.The liquid exits therefore the diverging surfaces at a reduced speed cantherefore gently exit the flow restrictor without splashing.

The position of the conical element 34 can be adjusted within thehousing so as to adjust the flow section. The more the element 34 isinserted into the housing, the lower the flow section will be and viceversa. This position can be adjusted by inserting reference washers orany other spacer(s) between the element 34 and the cap 28 ².Alternatively, a lever acting on a cam abutting against the conicalelement could be provided for manually adjusting the position of theelement without opening the flow restrictor 24. The end of the element34 that abuts against the cap 28 ² is plate-shaped and comprisesapertures for permitting the liquid to flow to the outlet 32.

The presence of the flow restrictor 24 is particularly interesting forit permits to keep a certain level of pressure upstream, i.e. in themixing chamber 18 (FIG. 1) and in the mixing unit 20 (FIG. 1).

The mixing unit 20 of FIG. 1 is illustrated in FIGS. 3 and 4. The mixingunit is composed of a corrugated flexible pipe 20 of the type that isillustrated in FIG. 3. Such a pipe is as such available on the marketand typically is characterized, among others, by its internal diameterd, its external diameter D, the height of its corrugation ridge h (thatcorresponds to (D−d)/2), the distance/between two adjacent corrugationridges and the wall thickness e. The pipe is preferably made ofstainless steel with an internal diameter d that is comprised between 5mm and 25 mm, preferably between 8 mm and 20 mm, more preferably between10 mm and 15 mm. The pipe is preferably a flexible stainless steelcorrugated pipe with a plastic external sleeve. The height of thecorrugation ridges is preferably comprised between 5% and 20% of theinternal diameter of the pipe. The distance/between adjacent ridges ispreferably comprised between 5% and 35%, preferably between 15% and 30%of the internal diameter of the pipe. The pipe 20 has a length that isof at least 0.8 m, preferably at least 1.0 m, more preferably at least1.2 m. This length can also be less than 5 m, preferably less than 2 m,more preferably less than 1.5 m.

FIG. 4 illustrates an embodiment of the device of FIG. 1. The device 1comprises as water source a connection 3 to a water distributionnetwork. The pump 4 pressurized the water for flowing through the mixingventure nozzle 8, the mixing chamber 18, the pipe 20 and the flowrestrictor 24. A bottle or cylinder 6 of pressurized gas is coupled tothe pressure reducer 26, this latter being fluidly connected to themixing venture nozzle 8 via the conduit 5.

We can observe that the mixing unit formed by the pipe 20 comprises aseries of bends along the length of the pipe in order to be compact.These bends can be of at least 90° or 180°.

The pump 4 is configured to pressurize the liquid at a pressure at theentry of the mixing venture nozzle that is of at least 8 bar, preferably9 bar, more preferably 10 bar. Due to the pressure drop that is inherentof the mixing venture nozzle, the mixing chamber 18 and the pipe 20, thepressure at the exit of the pipe 24, i.e. before the flow restrictor 24is of about 8 bar when the pressure at the entry of the mixing venturenozzle of about 10 bar. Under such conditions, the liquid mixed with thecarbon dioxide can therefore circulate along a substantial length ofcorrugated pipe at a relatively high pressure, thereby permitting aprogressive dissolving of the gas into the liquid with however a veryreduced pressure drop. The presence of the flow restrictor permits thepressure of the liquid to be reduced to atmospheric pressure when beingtapped, with a progressive deceleration. This deceleration avoids rapidescape of the dissolved carbon dioxide and consequent splashing at thetap exit.

The above described device and corresponding carbonating process permitsto achieve a high level of carbonation, i.e. at least 5 gr/liter andeven of 8 gr/liter, with a device of simple construction. The device canachieve this carbonation level at room temperature, i.e. without coolingsystem.

1.-19. (canceled).
 20. A device for dissolving a gas into a liquid,comprising: a pump configured to pump the liquid; a mixing venturenozzle having a main inlet fluidly connected to the pump and at leastone side inlet connectable to a source of pressurized gas; an outlet; aconical flow restrictor fluidly downstream of the mixing venture nozzle;and a pipe having a length of at least 0.5 m fluidly interconnectedbetween the mixing venture nozzle and the flow restrictor.
 21. Thedevice according to claim 20, wherein the pipe comprises one of thefollowing: a corrugated pipe; a flexible corrugated pipe; a flexiblestainless steel corrugated pipe; and a flexible stainless steelcorrugated pipe with a plastic external sleeve.
 22. The device accordingto claim 21, wherein the corrugated pipe forms corrugation ridges with aheight h comprising: between 5% and 20% of the internal diameter d ofthe pipe and/or with a distance/between adjacent ridges comprising oneof the following: between 5% and 30% of the internal diameter of thepipe; and between 10% and 20% of the internal diameter of the pipe. 23.The device according to claim 20, wherein the pipe has an internaldiameter d comprising one of the following: between 5 mm and 25 mm;between 8 mm and 20 mm; and between 10 mm and 15 mm.
 24. The deviceaccording to claim 20, wherein the pipe has a wall thickness ecomprising: between 0.15 mm and 0.3 mm.
 25. The device according toclaim 20, wherein the length of the pipe comprises one of the following:at least 0.8 m; at least 1.0 m; and at least 1.2 m.
 26. The deviceaccording to claim 20, wherein the length of the pipe comprises one ofthe following: less than 5 m; less than 2 m; and less than 1.5 m. 27.The device according to claim 20, wherein the pipe is bent at multipleplaces, so as to form a compact unit, the bends being made at one of thefollowing: over at least 90°; and over about 180°.
 28. The deviceaccording to claim 20, wherein the pump is configured to pressurize theliquid between the pump and the mixing venture nozzle at one of thefollowing pressures: at least 8 bar; 9 bar; and 10 bar.
 29. The deviceaccording to claim 20, wherein the conical flow restrictor is configuredto maintain a pressure in the pipe while debiting the liquid that iscomprised of one of the following: between 6 bar and 10 bar; and between7 bar and 9 bar.
 30. The device according to claim 20, wherein the flowsection of the conical flow restrictor progressively increases in thedirection of the flow.
 31. The device according to claim 20, wherein theconical flow restrictor comprises: a housing with a circular internalsurface that diverges in the direction of the flow; and a conicalelement inside the housing delimiting with said diverging internalsurface an annular flow section.
 32. The device according to claim 20,wherein the minimal flow section of the conical flow restrictor iscomprised of one of the following: between 1 mm² and 10 mm²; between 2mm² and 8 mm²; and between 2.8 mm² and 5.6 mm².
 33. The device accordingto claim 20, further comprising: a shut-off valve fluidly disposedbetween the conical flow restrictor and the mixing venture nozzle. 34.The device according to claim 20, further comprising: a mixing chamberfluidly connected to the outlet of the mixing venture nozzle, the mixingchamber being directly coupled to the mixing venture nozzle, so that themixing chamber is a direct extension of the outlet of the venturenozzle.
 35. The device according to claim 20, further comprising: apressure-reducer fluidly connected between, on one side, the pump andthe source of pressurized gas, and, on the other side, the main inletand the at least one side inlet of the mixing venture nozzle, thepressure-reducer being configured for adapting the pressure of the gasat the at least one side inlet to the pressure of the liquid produced bythe pump.
 36. A process for dissolving a gas into a liquid, comprising:providing a circuit having a mixing venture nozzle; pressurizing theliquid in the circuit; adding the gas to the liquid flowing through themixing venture nozzle by connecting at least one side inlet of theventure nozzle to a source of the pressurized gas; providing a conicalflow restrictor fluidly downstream of the mixing venture nozzle; andfluidly interconnecting a pipe of a length of at least 0.5 m between themixing venture nozzle and the flow restrictor.
 37. The process accordingto claim 36, further comprising: providing a pump; and pressurizing theliquid with the pump.
 38. The process according to claim 36, furthercomprising: using the flow restrictor and the pump to keep the pressurein the pipe at one of the following pressure ranges: between 6 bar and10 bar; and between 7 bar and 9 bar.